Connection device with movable bushing

ABSTRACT

Disclosed is a connection device for connecting an end section of a tube, comprising: a tubular body defining a channel, holding means for securing the tube end section within the channel in a sealed manner, and a bushing mounted in the channel to slide between a standby position in which the bushing is spaced apart from a stop at its recess within the channel and a recessed operating position in which the bushing presses against the stop. The bushing comprises, downstream from the holding means by reference to a direction of insertion of the end section of the tube into the body, at least one leg arranged to oppose the movement of the bushing toward the operating position and to be retracted by the end section of the tube when the bushing is engaged within the end section of the tube over a predetermined length.

BACKGROUND OF THE INVENTION

The present invention relates to the field of fluid transport circuits, in particular in motor vehicles, such as lorries, like for example, hydraulic braking circuits.

It is known to connect a tube to another element (other tube, dispenser, actuator, valve, etc.) of a pressurised fluid transport circuit by means of a connection device comprising a body defining a channel having a first section arranged to receive an end portion of the tube and a second section connected to said other element. Conventionally, the first section is provided internally with means for securing the tube end portion in the channel, in a sealed manner. These means generally comprise a fastening element such as a clamp, a slotted circlip or an internal tooth washer, and a sealing element such as an annular seal to be compressed between an outer surface of the tube and an inner surface of the channel.

A leakage of the connection device irremediably leads to a decrease on the pressure of the fluid circulating in the circuit, which can prove to be dangerous and lead to serious damage, in particular in a circuit of a vehicle braking system where the pressure decrease risks making said braking system inoperable.

It seems that the presence of a leakage in the fluid transport circuits is often due to an incorrect assembly of the tube with the connection device. It is indeed common that the tube is not sufficiently press-fitted in the body of the connection device to be engaged in the sealing element. An incorrect press-fitting generally occurs, because it is not easy to distinguish during press-fitting, the insertion of the tube in the fastening element, the insertion of the tube in sealing element, and finally the arrival of the stopped tube, to be assumed that there is one of them. This is all the more difficult, that there are numerous types of connectors which bring into play different forces and give the operator different sensations.

It is therefore advantageous to have a tube connection end control in order to be sure that the tube is sufficiently press-fitted in the connector to guarantee the sealing of the connection device.

A solution consists of making a mark on the outer surface of the tube, which is concealed by the body of the connector when the tube is sufficiently press-fitted in the connector. This solution therefore assumes that the operator thinks about making said mark on the tube , alternatively they will think that the tube is correctly connected, while it is not sufficiently press-fitted in the body of the device to cooperate with the holding means.

OBJECT OF THE INVENTION

The invention therefore aims to propose a connection device enabling to obviate, at least partially, the abovementioned problems.

SUMMARY OF THE INVENTION

To this end, a connection device of a tube end section is provided, according to the invention, comprising: a tubular body defining a channel, holding means for securing the tube end section in the channel, in a sealed manner, and a bushing comprising an end portion intended to be engaged in the tube end section. According to the invention, the bushing is mounted in the channel to slide between a standby position in which the bushing is spaced apart from the stop at its recess in the channel and a recessed operating position in which the bushing presses against the stop. The bushing comprises, downstream from the holding means by reference to a direction of insertion of the tube end section in the body, at least one leg arranged to press against a projection of the channel when the bushing is in the standby position and to oppose the movement of the bushing toward the operating position and to be covered by the tube end section which retracts the leg when the bushing is engaged in the tube end section over a predetermined length.

Thus, under a recessing force exerted by an operator, the tube is engaged on the bushing and covers the leg by folding back on it, which causes the retraction of the leg from the bushing. This retraction will enable a sudden recessing of the bushing to the recessed operating position, showing the end of the connection operation. As the leg is located downstream from the holding means, it is ensured that the tube end section is correctly engaged in the holding means when the bushing arrives in the recessed operating position (the predetermined length corresponding to the recess depth of the tube T, sufficient such that the latter cooperates with the holding means).

Other characteristics and advantages of the invention appear on reading the following description of a particular and non-limiting embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference is made to the accompanying drawings, in which:

FIG. 1 a is a longitudinal cross-sectional view of a connection device according to a first embodiment of the invention, awaiting a tube;

FIG. 1 b is a longitudinal cross-sectional view of the connection device according to the first embodiment of the invention, at the start of connecting a tube;

FIG. 1 c is a longitudinal cross-sectional view of the connection device according to the first embodiment of the invention, after a first recess stroke of the tube;

FIG. 1 d is a longitudinal cross-sectional view of the connection device according to the first embodiment of the invention, after a second recess stroke of the tube;

FIG. 1 e is a longitudinal cross-sectional view of the connection device according to the first embodiment of the invention, at the end of the connection of the tube;

FIG. 1 f is a longitudinal cross-sectional view of the connection device according to the first embodiment of the invention, after the pressurising of the circuit;

FIG. 2 a is a partial view of a connection device according to a second embodiment of the invention, awaiting a tube, represented as a longitudinal cross-section according to a first section plane;

FIG. 2 b is a partial view of the connection device according to the second embodiment of the invention, awaiting a tube, represented as a longitudinal cross-section according to a second section plane perpendicular to the first section plane;

FIG. 3 a is a partial view of the connection device according to the second embodiment of the invention, at the end of connection of the tube, represented as a longitudinal cross-section according to a first section plane;

FIG. 3 b is a partial view of the connection device according to the second embodiment of the invention, at the end of connection of the tube, represented as a longitudinal cross-section according to a second section plane perpendicular to the first section plane;

FIG. 4 a is a partial view of the connection device according to the second embodiment of the invention, after the pressurising of the circuit, represented as a longitudinal cross-section according to a first section plane;

FIG. 4 b is a partial view of the connection device according to the second embodiment of the invention, after the pressurising of the circuit, represented as a longitudinal cross-section according to a second section plane perpendicular to the first section plane;

FIG. 5 a is a partial view of a connection device according to third embodiment of the invention, awaiting a tube, represented as a perspective;

FIG. 5 b is a partial view of the connection device according to the third embodiment of the invention, awaiting a tube, represented as a front view;

FIG. 5 c is a partial view of the connection device according to the third embodiment of the invention, awaiting a tube, represented as a side view;

FIG. 6 a is a partial view of the connection device according to the third embodiment of the invention, after connection of a tube, represented as a perspective;

FIG. 6 b is a partial view of the connection device according to the third embodiment of the invention, after connection of a tube, represented as a front view;

FIG. 6 c is a partial view of the connection device according to the third embodiment of the invention, after connection of a tube, represented as a side view;

FIG. 7 a is a detailed view of the connection device according to the third embodiment of the invention, awaiting a tube, represented as a longitudinal cross-section according to a first section plane;

FIG. 7 b is a detailed view of the connection device according to the third embodiment of the invention, awaiting a tube, represented as a longitudinal cross-section according to a second section plane perpendicular to the first section plane;

FIG. 8 a is a detailed view of the connection device according to the third embodiment of the invention, at the end of connection of the tube, represented as a longitudinal cross-section according to a first section plane;

FIG. 8 b is a detailed view of the connection device according to the third embodiment of the invention, at the end of connection of the tube, represented as a longitudinal cross-section according to a second section plane perpendicular to the first section plane;

FIG. 9 a is a partial view of the connection device according to the third embodiment of the invention, awaiting a tube, represented as a longitudinal cross-section according to a first section plane;

FIG. 9 b is a partial view of the connection device according to the third embodiment of the invention, awaiting a tube, represented as a longitudinal cross-section according to a second section plane perpendicular to the first section plane;

FIG. 10 a is a partial view of the connection device according to the third embodiment of the invention, at the start of connection of a tube, represented as a longitudinal cross-section according to a first section plane;

FIG. 10 b is a partial view of the connection device according to the third embodiment of the invention, at the start of connection of a tube, represented as a longitudinal cross-section according to a second section plane perpendicular to the first section plane;

FIG. 11 a is a partial view of the connection device according to the third embodiment of the invention, during connection of the tube, represented as a longitudinal cross-section according to a first section plane;

FIG. 11 b is a partial view of the connection device according to the third embodiment of the invention, during connection of the tube, represented as a longitudinal cross-section according to a second section plane perpendicular to the first section plane;

FIG. 12 a is a partial view of the connection device according to the third embodiment of the invention, at the end of connection of the tube, represented as a longitudinal cross-section according to a first section plane (a) and as a longitudinal cross-section according to a second section plane perpendicular to the first;

FIG. 12 b is a partial view of the connection device according to the third embodiment of the invention, at the end of connection of the tube, represented as a longitudinal cross-section according to a second section plane perpendicular to the first section plane;

FIG. 13 a is a partial view of the connection device according to the third embodiment of the invention, after the pressurising of the circuit, represented as a longitudinal cross-section according to a first section plane;

FIG. 13 b is a partial view of the connection device according to the third embodiment of the invention, after the pressurising of the circuit, represented as a longitudinal cross-section according to a second section plane perpendicular to the first section plane.

DETAILED DESCRIPTION OF THE INVENTION

The invention is, in this case, described in application to the connection of a tube T to a fluid transmitter and/or receiver element belonging to a fluid transport circuit which cannot be seen in the figures. Said circuit element can be another tube, a dispenser, a pump, a reservoir, an actuator like a jack or a motor, or any other element of a fluid transport circuit.

In reference to FIG. 1 , and according to the first embodiment of the invention, the connection device, generally referenced in 1, comprises a tubular body 2 axially divided into a connection section at an end section of the tube T and a connection section at the circuit element. The tubular body 2 defines a channel 3 successively comprising an inlet section 3.1 connected via a counterbore 3.2 to a main section 3.3 intended to be in communication with a channel of the circuit element.

A movable assembly generally referenced in 4 is mounted in the inlet section 3.1. The movable assembly 4 comprises a bushing 5 and an insert 6 receiving holding means 7 for securing the end section of the tube in the channel 3, in a sealed manner.

The movable assembly 4 can slide between a standby position (FIG. 1 a, b, c) in which the bushing 5 is spaced apart from a bottom of the counterbore 3.2 forming a stop at its recess in the channel 3 and a recessed operating position (FIG. 1 d, e, f) in which the bushing 5 presses against the bottom of the counterbore 3.2.

The bushing 5 comprises an internal socket 5.1 connected by a collar 5.2 to an external socket 5.3 coaxial to the internal socket 5.1. The collar 5.2 extends facing the bottom of the counterbore 3.2.

The internal socket 5.1 has a first end in the vicinity of a free end of the insert 6 and a second end, in this case, connected to the collar 5.2. The second end of the internal socket 5.1 is extended beyond the collar 5.2 by two legs 5.4 diametrically opposite, pressing against the bottom of the counterbore 3.2 when the movable assembly 4 is in the standby position to oppose the movement of the movable assembly 4 toward the operating position. More specifically, the legs 5.4 press against a chamfer arranged in the bottom of the counterbore 3.2 around the outlet of the main section 3.3.

The external socket 5.3 comprises:

-   -   a part of a smaller diameter (slightly less than the diameter of         the counterbore 3.2) which is connected to the end collar 5.2         and which supports an annular seal 8, elastically radially         compressible, to ensure the sealing between the wall of the         inlet section 3.1 of the channel 3 and the outer surface of the         part of the smaller diameter;     -   a part of a greater diameter (slightly less than the diameter of         the inlet section 3.1) which is connected to the part of a         smaller diameter, which is engaged in an end of the insert 6         opposite its free end and which is provided internally with an         annular seal 9, elastically radially compressible, to ensure the         sealing between the outer surface of the tube T and the inner         surface of the part of a greater diameter.

The insert 6 is provided internally with a shoulder 6.1 which confines a fastening washer 10, internally teethed, with the free end of the external socket 5.3 and a dust-resistant annular seal 11 blocked in the free end of the insert 6 facing the free end of the internal socket 5.1 to prevent the passage of dust between the tube T and the inner surface of the insert 6.

The insert 6 is further externally provided with a groove 6.2 receiving an anchoring element 12 of annular shape such that:

-   -   when the movable assembly 4 is in the standby position, the free         end of the insert 6 and the anchoring element 12 extending         parallel to the outside projecting from the channel 3;     -   when the movable assembly 4 is in the operating position, the         free end of the insert 6 is flush with the body 2 and the         anchoring element 12 is totally received in the channel 3.

The anchoring element 12 comprises:

-   -   a first external step 12.1 arranged to be received in a first         housing 3.11 of the inlet section 3.1 when the movable assembly         4 is in the standby position to oppose an extraction of the         movable assembly 4 outside of the channel 3; and     -   a second external step 12.2, higher than the first step 12.1 and         arranged upstream from this by reference to the direction of         insertion of the tube T in the channel 3, arranged to be         received in a second housing 3.12 of the inlet section 2.1 when         the movable assembly 4 is in the operating position so as to         oppose an extraction of the movable assembly 4 outside of the         channel 3.

The anchoring element 12 is thus arranged to oppose an extraction of the insert outside of the channel 3 in each of the positions of the movable assembly 4 and therefore of the bushing 5.

The anchoring element 12 is an annular slotted circlip which can be elastically deformed in a rest state in which the second step 12.2 has an outer diameter greater than the inner diameter of the second housing 3.12 and a deformed state in which the second step 12.2 has an inner diameter less than the inner diameter of the inlet section 3.1. The first step 12.1 and the second step 12.2 have a downstream surface (by reference to the direction of insertion of the tube T in the channel 3) inclined to facilitate the elastic deformation of the anchoring element 12 and the recessing of the movable element 4 in the channel 3 and an upstream surface (by reference to the direction of insertion of the tube T in the channel 3), radial or quasi-radial to oppose the extraction of the movable assembly 4 outside of the channel 3 by cooperating with a homologous surface of the housings 3.11, 3.12 respectively.

Before any connection (FIG. 1 a ), the movable assembly 4 is in the standby position and the anchoring element 12 is partially projecting from the channel 3, the first step 12.1 being received in the first housing 3.11.

At the start of the connection, the end section of the tube T is simultaneously engaged on the free end of the internal socket 5.1 and in the dust-resistant seal 11, the movable assembly 4 being held in the standby position by the legs 5.4 pressing against the bottom of the counterbore 3.2 in the vicinity of the outlet of the main section 3.3.

The recessing force of the tube T is continued, the end section of the tube T passes into the fastening washer 10 and into the seal 9 (FIG. 1 b ), the movable assembly 4 being held in the standby position by the legs 5.4 pressing against the bottom of the counterbore 3.2.

The recessing force of the tube T being continued, the end section of the tube T progressively covers the legs 5.4 by exerting on them, a force having a radial component which tends to elastically deform them to fold them back toward the central axis of the body 2 (FIG. 1 c ), until forcing the folding back of the legs 5.4 which thus avoid being pressed against the bottom of the counterbore 3.2 and will return into the main section 3.3. It is therefore by a direct contact that the tube folds the legs back inwards and retracts them with respect to the bottom of the counterbore 3.2. This folding back of the legs 5.4 enables the movement of the movable assembly 4 toward the operating position (FIG. 1 d ). Simultaneously, the anchoring element 12 is elastically deformed due to the sliding of the steps 12.1, 12.2 against the body 2 like cams, and is located between the housings 3.11 and 3.12. The movement of the movable assembly 4 is relatively sudden and ends when the bushing 5 stops against the bottom of the counterbore 3.2 (FIG. 1 e ). The second step 12.2 thus arrives facing the second housing 3.12 and has penetrated there under the effect of the elasticity of the anchoring element 12 which has flattened the second step 12.2 against the bottom of the second housing 3.12. It is understood that, the legs 5.4 extending downstream from the holding means 7 (i.e. downstream from the seal 9 and from the anchoring washer 10) by reference to the direction of insertion of the end section of the tube T in the body 2, the movable assembly 4, and therefore the bushing 5, only moves toward the operating position, once the tube T section is in a correct connection position with respect to the holding means 7.

The arrival of the bushing 5 in the second recessing position thus activates at least one connection control. In this first embodiment, there are several connection controls:

-   -   the bushing 5 and the body 2 are made of materials such that the         arrival of the bushing 5 stopped against the bottom of the         counterbore 3.2 (in the operating position) causes a sound         constituting a connection control;     -   the anchoring element 12 extends projecting from the body 2 when         the movable assembly 4 (and therefore the bushing 5) is in the         standby position and is received completely in the body 2 when         the movable assembly 4 is in its operating position such that         the anchoring element 12 constitutes both a tactile connection         control and a visual connection control. The anchoring element         12 and the body 2 preferably have contrasting colours to         strengthen the visual signal constituted by the retraction of         the anchoring element 12 in the body 2;     -   due to the height of the second step 12.2 (greater than the         depth of the second housing 3.12) and the elasticity of the         anchoring element 12, the second external step 12.2 strikes the         bottom of the second housing 3.12 when the movable element 4         arrives in its operating position. The anchoring element 12 and         the body 2 are made of materials such that the arrival of the         second external step 12.2 against the bottom of the second         housing 3.12 causes a sound constituting a connection control.

Upon pressurising the circuit, the tube T will slightly go backward under the effect of the fluid pressure, but will be held in the insert 6 by the fastening washer 10 while the insert 6 will be held in the body 2 by the anchoring element 12. The groove 6.2 receiving the anchoring element 12 has an inclined downstream flank and a substantially radial upstream flank, the free edges of which define a opening wider than the bottom of the groove 6.2. The anchoring element 12 has, facing the flanks of the groove 6.2, downstream and upstream faces having inclinations, homologous to those of the flanks facing which they are located such that, when an extraction force is exerted on the tube T, the cooperation of the downstream flank of the groove 6.2 with the downstream face of the anchoring element 12 tends to make the anchoring element 12 project outside of the recess 6.2, thus strengthening the holding of the insert 6 in the channel 3.

Element identical or similar to those described above will have a numerical reference identical to the latter in the following description of the second and third embodiments in relation to FIGS. 2 to 13 .

In reference to FIGS. 2 to 4 , the connection device 1 according to the second embodiment comprises, as above: a body 2, a bushing 5, an insert 6, seals 8, 9 and 11.

This connection device has two main differences with respect to the first embodiment:

-   -   the insert 6 is fixed, only the bushing 5 is movable between the         standby position and the operating position which are the same         as above;     -   the insert 6 has no connection control and only the bushing 5 is         provided with connection controls.

The external socket 5.3 of the bushing 5 is, in this case, provided with two side arms 20 having a free end 21 provided with a bulge. The side arms 20 are diametrially opposite one another and are elastically deformable from a deformed state, in which the free ends are close to the internal socket 5.1 and a rest state, in which the free ends are spaced apart from the internal socket 5.1.

The body 2 is provided with two orifices 23 intended to receive the bulges of the free ends 21 when the bushing 5 is in its operating position.

Secondarily, the internally-toothed fastening washer 10 has been replaced by a slotted hooking ring 10′, intended to sandwich the end section of the tube T and the shoulder 6.1 has a truncated shape to favour a clamping of the hooking ring 10′ on the end section of the tube T when an extraction force is exerted on the tube T. The hooking ring 10′ is elastically deformable and comprises an internal projection to overlap the outer surface of the end section of the tube T.

Thus, before any connection (FIG. 2 a, 2 b ), the bushing 5 is in the standby position and the arms 20 are held in a deformed state by the bulges of the free ends 21 pressing against the wall of the inlet section 3.1 of the channel 3.

As above, at the start of the connection, the end section of the tube T is simultaneously engaged on the free end of the internal socket 5.1 and in the dust-resistant seal 11, the bushing 5 being held in the standby position by the legs 5.4 pressing against the bottom of the counterbore 3.2 in the vicinity of the outlet of the main section 3.3.

The recessing force of the tube T is continued, the end section of the tube T passes into the hooking ring 10′ and in the seal 9, the bushing 5 being held in the standby position by the legs 5.4 pressing against the bottom of the counterbore 3.2.

The recessing force of the tube T being continued, the end section of the tube T progressively covers the legs 5.4 and tends to elastically deform them to fold them back toward the central axis of the body 2, until forcing the folding back of the legs 5.4 which thus escape, pressing against the bottom of the counterbore 3.2 and return into the main section 3.3. This folding back of the legs 5.4 enables the movement of the bushing 5 toward the operating position. The movement of the bushing 5 is relatively sudden and ends when the bushing 5 stops against the bottom of the counterbore 3.2 (FIGS. 3 a and 3 b ). Simultaneously, the bulges of the free ends 21 of the arms 20 arrive facing the orifices 23 and have penetrated there under the effect of the elasticity of the arms 20. In doing this, the arms 20 come back into contact against the edge of the orifices 23. The free end 21 is thus movable between a visible position in which the free end 21 can be seen from the outside of the body 2 and a retracted position, in which the free end 21 is concealed from the outside of the body 2.

As above, the arrival of the bushing 5 in the second recessing position activates at least one connection control. In this second embodiment, there are several connection controls:

-   -   the bushing 5 and the body 2 are made of materials such as the         arrival of the bushing 5 stopped against the bottom of the         counterbore 3.2 (in the operating position) causes a sound         constituting a sound connection control;     -   the bulges of the free ends 21 are received in the orifices 23         and can be seen from the outside through the orifices 23 when         the bushing 5 is in the operating position, while they do not         appear when the bushing 5 is in the standby position. Thus, the         bulges of the free ends 21 constitute a visual connection         control. The arms 21 and the body 2 preferably have contrasting         colours to strengthen the visual signal constituted by the         appearance of bulges in the orifices 23;     -   due to the height of the bulge of the free end 21 of the arms 20         and of the elasticity of the arms 20, the arms 20 in the         vicinity of their free end 21 suddenly strike the wall of the         end section 3.1 when the bushing 5 arrives in its operating         position. The arms 20 and the body 2 are made of materials such         as the impact of the arms 20 against the wall of the inlet         section 3.1 causes a sound constituting a sound connection         control.

Upon pressurising the circuit, the tube T will slightly go backward under the effect of the fluid pressure, but will drive the hooking ring 10′ which will slide against the truncated surface of the shoulder 6.11 increasing the clamping of the slotted ring 10′ on the tube T (FIG. 4 a, 4 b ) and the insert 6 will oppose the extraction of the tube T.

In reference to FIGS. 5 to 13 , the connection device 1 according to the third embodiment comprises, as above: a body 2, a bushing 5, an insert, and seals 8, 9.

The connection device according to the third embodiment has two main differences with respect to the second embodiment:

-   -   the side arms 20 are replaced by first axial arms 20′;     -   the dust-resistant seal 11 is replaced by a dust-resistant seal         11′ having a different shape.

Furthermore, in the third embodiment, the insert 6′ is fixed in the inlet of the channel 3 like in the second embodiment, but has a structure different from that of the second embodiment.

The external socket 5.3 of the bushing 5 has a free end, of which two first axial arms 20′ having a free end 21′ are integral. The first axial arms 20′ are diametrically opposite one another and pass through the insert 6′ in bores 6.4′ such that their free ends 21′ extend axially projecting from the face 6.3′ of the insert 6′ through openings 6.5′ when the bushing 5 is in the standby position (FIGS. 5 and 7 ) and are retracted when the bushing 5 is in the operating position (FIGS. 6 and 8 ).

The free end of the external socket 5.3 of the bushing 5 is also provided with two second axial arms 30 having a free end 31. The second axial arms 30 are diametrically opposite one another and are inserted between the first axial arms 20′. The second axial arms 30 are elastically deformable between a deformed state in which the free ends 31 are close to the central axis of the external socket 5.3 and a rest state in which the free ends 31 are spaced apart from the central axis of the external socket 5.3. The second axial arms 30, shorter than the first axial arms 20′, are received in axial conduits 6.8′ of the insert 6′. The second axial arms 30:

-   -   are held in their deformed state by the walls of the conduits         6.8′ of the insert 6′ when the bushing 5 is in its standby         position (FIGS. 5 and 7 ), and     -   have, when the bushing 5 is in the operating position, their         free ends 31 facing orifices 6.9′ opening into the conduits 6.8′         and enabling an elastic return of the second axial arms 30         toward their rest state such that the free ends 31 are         projecting into said orifices 6.9′ (FIGS. 6 and 8 ).

The seal 11′ has the shape of a cap covering the end of the body 2 in which the insert 6′ is inserted. The seal 11′ is pierced with a central opening for the passage of the tube T and slots 11.1′ in vertical alignment with the openings 6.5′ and can comprise an edge sandwiching an annular portion of the side wall of the body 2 or be overmoulded on the insert 6′.

Thus, before any connection (FIG. 9 a, b ), the bushing 5 is in the standby position and the free ends 21′ of the arms 20′ project through the openings 6.5′ and the slots 11.1′.

As above, at the start of the connection (FIG. 10 a, b ), the end section of the tube T is simultaneously engaged on the free end of the internal socket 5.1 and in the dust-resistant seal 11′, the bushing 5 being held in the standby position by the legs 5.4 pressing against the bottom of the counterbore 3.2 in the vicinity of the outlet of the main section 3.3.

The recessing force of the tube T being continued, the end section of the tube T passes into the hooking ring 10′ and into the seal 9, the bushing 5 being held in the standby position by the legs 5.4 pressing against the bottom of the counterbore 3.2 (FIG. 11 a, b ).

The recessing force of the tube T being continued, the end section of the tube T progressively covers the legs 5.4 and tends to elastically deform them to fold them back toward the central axis of the body 2, until forcing the folding back of the legs 5.4 which thus escape, pressing against the bottom of the counterbore 3.2 and return into the main section 3.3. This folding back of the legs 5.4 enables the movement of the bushing 5 toward the operating position. The movement of the bushing 5 is relatively sudden and ends when the bushing 5 stops against the bottom of the counterbore 3.2 (FIG. 12 a and b ).

Simultaneously, the free ends 21′ of the arms 20′ are retracted and the slots 11.1′ close while the free ends 31 arrive facing the orifices 6.9′ such that the second axial arms 30 elastically return to their rest state, striking the wall of the insert 6′ in the surroundings of the orifice 6.9′. It is noted that the slots 11.1′ are defined by two lips in contact with one another when the ends 21′ are retracted, which has two advantages: the dust-resistant seal 11′ prevents dust getting in via the openings 6.9′ and conceals the ends 21′ in full view. The free end 21′ is thus movable between a visible position in which the free end 21′ can be seen from the outside of the body 2 and a retracted position in which the free end 21′ is concealed from the outside of the body 2.

As above, the arrival of the bushing 5 in the second recessing position activates at least one connection control. In this third embodiment, there are several connection controls:

-   -   the bushing 5 and the body 2 are made of materials such that the         arrival of the bushing 5 stopped against the bottom of the         counterbore 3.2 (in the operating position) causes a sound         constituting a connection control;     -   the free ends 21′ extend projecting from the insert 6′ and from         the dust-resistant seal 11′ when the bushing 5 is in the standby         position and are received completely in the conduits 6.4′ when         the bushing 5 is in its operating position, such that the first         axial arms 20′ constitute both a tactile connection control and         a visual connection control. The first axial arms 20′ and the         dust-resistant seal 11′ preferably have contrasting colours to         strengthen the visual signal constituted by the retraction of         the free ends 21′ in the conduits 6.4′;     -   due to the elasticity of the second axial arms 30, the second         axial arms 30, in the vicinity of their free ends 31, strike the         wall of the conduits 6.8′ in the vicinity of the orifices 6.9′         when the bushing 5 arrives in its operating position. The second         axial arms 30 and the insert 6′ are made of materials such that         the impact of the second axial arms 30 against the wall of the         conduits 6.8′ causes a sound constituting a sound connection         control.

Upon pressurising the circuit, the tube T will slightly go backward under the effect of the fluid pressure, but will be, as above, held in the insert 6′ by the hooking ring 10′ which will slide against the truncated surface of the shoulder 6.1′ increasing the clamping of the hooking ring 10′ on the tube T (FIG. 13 a and b ).

Naturally, the invention is not limited to the embodiments described, but covers any variant coming within the scope of the invention such as defined by the claims.

In particular, the tubular body can have a structure different from that described, likewise the means for ensuring the sealing of the connection and the securing of the tube end. It is thus possible to have an instantaneous connection by means of a clamp, a radial bolt or a toothed washer, or a non-instantaneous connection by screwing or otherwise. It is possible to provide a deconnection pushbutton to act on the hooking element so as to be able to extract the tube T.

The holding means can be supported or not by an insert, integral in translation with the bushing.

The insert cannot be integral in translation with the bushing.

The anchoring element of the insert can be arranged to oppose an extraction of the insert outside of the channel in only one of the positions of the bushing. It is possible to have one anchoring element per position.

The bushing 5 can comprise one or more legs 5.4. The leg(s) can have a shape and/or an arrangement different from those described.

The leg 5.4 is arranged to press against a projection of the channel 2 when the bushing 5 is in the standby position so as to oppose the movement of the bushing 5 toward the operating position. The projection can be formed by the stop at the recessing of the bushing 5 in the channel 2 beyond the operating position, or by a projection separate from this stop. 

1. Connection device of a tube end section, comprising: a tubular body defining a channel, holding means for securing the tube end section in the channel in a sealed manner, and a bushing comprising an end portion intended to be engaged in the tube end section, characterised in that the bushing is mounted in the channel to slide between a standby position in which the bushing is spaced apart from a stop at its recessing into the channel and a recessed operating position, in which the bushing presses against the stop, and in that the bushing comprises, downstream from the holding means by reference to a direction of insertion of the tube end section in the body, at least one leg arranged to press against a projection of the channel when the bushing is in the standby position and to oppose the movement of the bushing toward the operating position and to be covered by the tube end section which retracts the leg when the bushing is engaged in the tube end section over a predetermined length.
 2. The connection device according to claim 1, arranged such that the arrival of the bushing in the recessed position activates a connection control.
 3. The connection device according to claim 2, wherein the bushing and the body are made of materials such that the arrival of the bushing stopped in its recessed position causes a sound constituting the connection control.
 4. The connection device according to claim 1, wherein the holding means are supported by an insert integral in translation with the bushing to form a movable assembly.
 5. The connection device according to claim 4, wherein the insert is provided externally with an anchoring element of the insert in the channel to oppose an extraction of the insert outside of the channel in at least one of the positions of the movable assembly.
 6. The connection device according to claim 5, wherein the anchoring element is arranged to oppose an extraction of the insert outside of the channel in each of the positions of the movable assembly.
 7. The connection device according to claim 5, wherein the anchoring element extends projecting from the body when the bushing is in the standby position and is received completely in the channel when the bushing is in its recessed position such that the anchoring element constitutes a connection control.
 8. The connection device according to claim 7, wherein the anchoring element and the body have contrasting colours.
 9. The connection device according to claim 5, wherein the anchoring element is received in a groove which is arranged in the insert and which has an inclined downstream flank and the anchoring element has, facing the downstream flank of the groove, a downstream face having an inclination homologous to that of the downstream flank such that, when an extraction force is exerted on the tube, the cooperation of the downstream flank of the groove with the downstream face of the anchoring element tends to make the anchoring element project outside of the groove.
 10. The connection device according to claim 1, wherein the holding means are supported by an insert mounted fixed in the channel and the bushing supports at least one arm having an end which can be seen from the outside of the body for one of the positions of the bushing and invisible from the outside of the body for the other of the positions of the bushing.
 11. The connection device according to claim 1, the projection being formed by the stop at the recessing of the bushing in the channel. 